Many toner cartridges available for laser printers contain significant mechanical elements employed in the electrophotographic printing process which are subject to wear or failure. By incorporating such elements in the toner cartridge, this has reduced the need for service calls to outside technicians by alleviating the need to repair these printer elements, since these elements are replaced on a regular basis when a new toner cartridge is installed. The increased complexity of these "all-in-one" cartridges and the concomitant increase in the value of these cartridges (due to the complexity of the incorporated mechanical elements) has resulted in substantially increased efforts towards collection and remanufacture of exhausted toner cartridges.
Several approaches to remanufacturing these cartridges are currently being practiced. These methods typically incorporate a method of sealing the toner supply portion of the cartridge to prevent toner leakage during shipment. These seals are then removed by the printer operator when installing the cartridge into the printer. One method currently in use to seal the toner supply portion of the cartridge is to insert a seal through the original seal removal slot. A second method currently in use involves splitting the toner supply portion of the cartridge apart from the portion of the cartridge that contains the mechanism for tribo-charging and delivering charged toner to the photoreceptor (where the latent xerographic image is transformed to a visible image through the well-known xerographic process). With these two portions of the cartridge physically separated from each other, the toner supply sealing face is exposed, facilitating the installation of a new toner seal.
After recharging the toner cartridge, the assembly is resealed and reassembled. One known method of reassembly is to reconnect the toner hopper to the toner charging and delivery section using spring clips. These clips may be in the form of a plurality of short clips spaced along the sections to be joined, or in the form of two long clips (each individual clip situated on opposing flanges on each side of the respective members being joined). The long clip approach is preferable for several reasons: (1) the short clips represent a hazard to the printer since a single short clip, if it becomes disengaged, can fall into the paper transport region of the printer where it can cause significant damage to the mechanism; (2) the short clips present a plurality of protruding edges that can cause injury to a person handling the cartridge; and (3) the long clips present a more uniform clamping pressure and a more pleasing appearance, in comparison to the short clips.
Several cartridge models available today, such as those based on the Canon WX engine, including the Hewlett Packard LaserJet 5si, are not amenable to the use of long clips, due to the protrusion of obstacles into the area of the mating flanges, which prevent the long clips from being fully installed along the flange edge. These obstacles typically consist of reinforcing ribs or similar protrusions molded into one or both of the mating flanges of the two members being joined.